Approximately 30 - 50% of known HIV-infected individuals in the United States are believed to be inadequately engaged in primary medical care for their HIV infection [1-4]. Morbidity and mortality are disproportionately high in these individuals [5, 6]. Over the last several years there has been a growing interest in understanding the barriers to long-term retention in HIV care. Most existing retention in care research has defined this population and, more recently, assessed outcomes of poor retention in care. The next step has also begun - identifying effective interventions to improve engagement in HIV care. This progression of research focus has paralleled what occurred for antiretroviral medication adherence research over the last ten years. Although numerous interventions to improve adherence to antiretroviral medications have been successful, it has been found that many of these primarily behavioral interventions may be limited by having waning effects, being time consuming, costly to implement, and difficult to sustain [8]. Promotion of engagement in care may be more amenable to structural interventions or system-level interventions than promotion of adherence to medications. System-level interventions may be easier to implement and more sustainable. They are also more likely to reach a larger target audience than other interventions. Finally, they may augment other types of interventions, such as behavioral interventions, by making it easier to identify the target population or by targeting populations who are different than those traditionally targeted by behavioral interventions. The overarching goals of this proposal are to develop and pilot a multifaceted intervention at the health care system-level to prevent lapses in medical care for HIV-infected individuals and to re-engage individuals who have had a lapse in medical care. The intervention is based on revamping health system informatics, collaborations with vital partners, and system-navigation for the target population. Specifically the aims of this research are to perform formative research to help define central questions about the intervention including the reasons for being out of care, the best way to predict lapses in care, and the best methods to find individuals who are out of care. This phase of research will involve a descriptive analysis of engagement in care in the entire population of HIV- infected individuals at our institution (Specific Aim 1) and qualitative interviews with HIV-infected individuals returning to care (Specific Aim 2). Next we will refine and standardize the intervention (Specific Aim 3). This will focus on refining 1) systems to identify the target population and 2) the outreach/navigation activities that will be utilized for the intervention. In this stage we will also perform pilot testing to assess feasibility and acceptability of the intervention among key stakeholders. This research proposal is being submitted to the National Institutions of Mental Health and aligns well with the institute's goal "to enhance and expand available intervention strategies to promote, improve, and sustain adherence," including adherence to medical care. PUBLIC HEALTH RELEVANCE: This project is being carried out to develop an intervention to improve engagement in primary medical care for HIV-infected individuals. In addition to the individual benefits of long-term retention in care derived from the use of prophylactic medications and antiretroviral therapy, there is a public health benefit to retention in care as well. Antiretroviral therapy decreases the risk of HIV transmission to at risk individuals]. In addition, HIV-infected individuals in care are less likely to engage in HIV transmission risk behaviors.